(1) Field of the Invention
The present invention relates to waterless urinals and, more particularly, to waterless urinal cartridges that include a mechanism for reducing the turbulence and/or splashing of fluids entering the cartridge in order to reduce precipitant buildup and to assist in cleaning.
(2) Description of Related Art
Water is a scarce and diminishing resource in many areas of the world. It is widely recognized that more has to be one to conserve its usage as populations grow and climates change. Water conserving products are becoming more and more important not only for quality of human life but also for sanitary and subsistence reasons.
There have been many water conserving measures taken all over the world in an effort to deal with limited and diminishing resources. Many municipalities have developed, rationing plans. Others have invested in waste water recycling treatment and re-use. There have also been many water-conserving products introduced into the marketplace. These products are being more widely used by industry and homeowners as regulations become stricter and the costs of water usage rise.
The non-flushing urinal designs use far less water than the traditional urinals, saving up to 40,000 gallons of water per year just from a single urinal. The non-flushing urinals are made of three major components: a porcelain urinal, a housing, and a cartridge. The porcelain urinal component is very similar to a traditional urinal. The housing replaces a traditional P-trap which normally would connect the urinal to the building's plumbing. Thus, the housing is placed in-line between the building's plumbing and the bottom of the urinal where the drain pipe would normally connect. The cartridge operates as the P-trap and fits in the housing in a sealed air-tight manner, and can be removed for servicing and replacement.
A liquid trap-style cartridge serves two purposes. First, it acts as a barrier from sewer gasses and odors coming into the restroom. Second, it acts as a filter; removing some of the solids that precipitate from the human urine (which is a super saturated liquid). The human urine is an aqueous solution of greater than 95% water, with the remaining constituents, in order of decreasing concentration being urea 9.3 g/L, chloride 1.87 g/L, sodium 1.17 g/L, potassium 0.750 g/L, creatinine 0.670 g/L, and other dissolved ions, inorganic and organic compounds according to the NASA Contractor Report No. NASA CR-1802, D. F. Putnam, July 1971.
The liquid trap-style cartridge works by using two mechanisms. First, urine fills the P-trap of the cartridge, forming a barrier against sewer gasses—just as the water does in a traditional P-trapped urinal. Second, a layer of low density fluid, such as oil, can be poured into the trap so that it floats on top of the urine. This floating fluid forms a barrier keeping unpleasant urine smells from entering the bathroom. As a user urinates into the urinal, fresh urine enters the cartridge, sinks through the floating fluid barrier, and presses the old urine out of the trap and out through the housing exit tube and into the building's plumbing. Thus it is critical for the fluid barrier to stay intact so it remains floating above the urine in the cartridge to keep foul smells from entering the restroom. If urine encounters the fluid barrier with either too much velocity or in too high a volume, the fluid that forms the barrier may be broken up into small particles and washed out with the urine.
Though there are a significant water saving benefits from using non-flushing urinals, some drawbacks exist. One of the most significant is the formation of struvite in the pipes, the housing, and the cartridge. Struvite (magnesium ammonium phosphate) is a phosphate mineral with formula: NH4MgPO4.6H2O. Struvite crystallizes in the orthorhombic system as white to yellowish or brownish-white pyramidal crystals or in platy mica-like forms. It is a soft mineral with a Mohs hardness of 1.5 to 2 and has a low specific gravity of 1.7. It is sparingly soluble in neutral and alkaline conditions, but readily soluble in acidic conditions. In some cases, formation of struvite in the cartridge can be beneficial, as struvite formed in the cartridge is struvite not deposited in the housing or the pipes. The cartridge is designed to be easily replaceable, thus its action as a filter is a benefit.
The manner in which struvite or other solids build up inside the cartridge is important, as the flow of new fluids (both flushing fluids and urine) is affected by where buildup occurs. While flushing urinals also produce buildup in the pipes, there it tends to be of more of a hard, calcified nature. With the non-flushing urinals, it has been found that struvite formation is more common, particularly in areas of slow velocity flows or high splash (both of which cause struvite to precipitate out of solution from the urine).
Struvite can also build up in the pipes of the plumbing lines, which are downstream from the cartridge. It is often desirable to flush these pipes out with fresh water; however to do so can be onerous, as it requires the removal of the cartridge prior to dumping a bucket of water into the urinal. This is to avoid flushing the protective floating oil barrier that prevents odor from entering the user environment. The lighter-than-urine barrier cannot withstand the dumping of high volumes of fluid into the traditional cartridge designs (for e.g., when a bucket of water is dumped into the cartridge) because the fluid entering the cartridge at high velocity impinges on the oil and breaks it up into small particles, flushing the oil through the cartridge.
Codes and regulations in many countries also affect cartridge design. In the United States, for example, the plumbing code typically requires a two inch vertical liquid barrier to sewer gasses. Thus, unless another component provides the trap action, the cartridge must be designed to hold a two inch column of water in order to comply with the plumbing code. Because the trap area is the area most likely to have struvite sediment clog it, it is advantageous for the cartridge (which is easily replaceable) to be the component that provides this two inch gas sealing water column as required by the plumbing code.
There are a number of different designs of the liquid trap cartridges. All United States code-compliant models utilize a 2″ deep water column to block sewer gas while some utilize a central exit and some utilize a side exit. Code compliant cartridges similar to those made by Falcon Waterfree Technologies (located at 2255 Barry Avenue, Los Angeles, Calif. 90064, USA) use a central inlet for fluid to enter and a side or a back exit for the fluid to exit the cartridge. Others, like the cartridge manufactured and sold under the Waterless brand (Waterless Co., 1050 Joshua Way, Vista, Calif. 92081, USA) utilize inlets spaced away from the center and closer to the perimeter of the cartridge, and a central cartridge, exit.
Various methods for trying to retain oil exist in the market today. However, none avoid the action of impingement and breaking up the oil into smaller, more soluble particles, which are easily flushed through the cartridge. Examples of solutions heretofore presented in the art include, but are not limited to, the mechanism shown in U.S. Pat. No. 6,425,411, which has a deflector siting above the inlet compartment's fluid level and the mechanism of Korean Patent No. KR20100013602A, which utilizes a deflector-like shelf within the cartridge fluid level. Neither of these solutions effectively prevents strong impingement of urine with the barrier fluid layer.
Thus, there is a need for a better non-flush cartridge inlet system. It is therefore desirable to provide waterless urinal cartridges that include a mechanism for reducing the turbulence and/or splashing of fluids entering, the cartridge in order to maintain the integrity of the barrier fluid layer and to reduce precipitant buildup and to assist in cleaning.